During the process flow of manufacturing a semiconductor integrated circuit, nearly more than one hundred steps are related to wafer surface cleaning and chemical processing, and these steps account for 25%-35% of the total production process steps. Among the wafer surface chemical processing and cleaning equipment used in the present integrated circuit manufacturing industry, nearly 70% of them are still traditional batch-type processing cleaning equipment and RCA-type cleaning methods.
With the continuous increase of wafer size (200 mm→300 mm→450 mm) in integrated circuit production and the continuous decrease of electronic component line width (65 nm→45 nm→32 nm), those traditional batch-type chemical processing and cleaning technologies (i.e. more than 25 wafers are processed every time) have faced increasing challenges, including problems of wafer surface processing uniformity and problems of cross contamination that possibly occurs in batch-type processing; the problem of inadequate removal capability for ultra-micro particles; the problem of ultrastructure damage from Megasonic technology, the problem of high difficulty in chemical processing and cleaning of the surface of new materials with low and high dielectric constants and the surface of metal grid electrodes, and so on. Meanwhile, due to these numerous factors such as actual needs in single-side wafer chemical processing and cleaning, wafer thinning, connection of online equipment, etc., a gradual transformation from traditional batch-type processing to single wafer processing is promoted in the aspect of semiconductor wafer cleaning technology.
In actual use, the advantages of the single wafer processing technology have been clearly reflected in wide application of the back end of line (BEOL) of IC, and have begun gradually expanding to the front end of line (FEOL) of IC. However, wide application of the single wafer processing technology in the FEOL of IC has been seriously restricted by the low throughput problem of the single wafer chemical processing equipment relative to the traditional multi-wafer batch-type processing equipment. The throughput gap between the single wafer chemical processing equipment and the traditional batch-type processing equipment cannot be properly bridged only by adding more single wafer chemical processing equipment, this is because rise in cost of the solution for addressing this problem is much faster than throughput improvement.
Therefore, there is a need to provide a better solution for settling the above problems.